Page 8 - Energize November 2022
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NEWS


        A breath of fresh air for a mining company



        Sasol Mining relies on Relion to ensure reliable power supply to new ventilation shaft




            asol Mining chose in favour of   reduction. For the new substation that feeds the new ventilation shaft, Sasol Mining
            the highly flexible ABB Relion®   chose a protection and control solution with ABB’s Relion relays from the product
       Sprotection relays for their new      family’s 615 and 620 series, as well as the all-in-one protection relay REX640 to be
        substation at the Syferfontein mine in   installed in the medium-volt-age switchgear. This is the first installation with ABB’s
        South Africa. The wide functionality,   Relion® protection and control relays for Sasol Mining.
        large event and fault recording        “A key consideration for us when deciding in favour of the Relion® relays was that
        capabilities, reduced footprint, as   they offered all the functionality we need,” said Divesh Ramasur, Senior Electrical
        well as cost reductions, were the key   Engineer at Sasol Mining. “They are also flexible and offer large event and fault
        factors.                             recording capabilities.”
           Sasol Mining is part of South       Sasol Mining chose these protection and control relays because they offer the
        African integrated energy and        needed circuit breaker control functions and have arc flash protection embedded for
        chemical company Sasol, undertaking   increased safety. They also have simpler GOOSE (Generic Object-Oriented Substation
        the coal mining operations. Sasol    Event) protocol utilisation and all have the R/L (remote/local) switch available on the
        Mining operates six coal mines that   relay faceplate for easier operation. Further, the customer chose Relion 620 series
        supply approximately 40 million tons   relays for motor protection. These relays offer stall protection functionality and also
        per annum of thermal coal feedstock.   thermal overload protection considering the actual starting time of the motor.
        At the company’s largest colliery, the   The installation of Relion relays has resulted in cost reduction and reduced
        Syferfontein mine in the Secunda     switchgear footprint. “With REX640 we can use only one relay for transformer
        area, Sasol Mining identified that the   protection, whereas earlier we had to use many different relays to achieve the same
        ventilation shaft was not sufficient   level of protection,” said Ramasur. “The REX640 relay has many protection functions
        to ensure the required aeration      available for transformer protection, such as low impedance differential protection,
        of the mining district. To ensure    low impedance restricted earth-fault protection, sensitive earth fault protection, and
        uninterrupted power supply to a new   tap changer control all integrated into the relay. On top of that it has many binary
        ventilation shaft, they needed a new   inputs and outputs, and the relay can incorporate many analogue inputs, too.”
        substation.                            As a result, the footprint of the switchgear was reduced, as there was no longer
           In underground mining,            the need to install three different relays to obtain the same functionality. The smaller
        ventilation systems are of paramount
        importance to ensure safe working
        conditions for people. Ventilation
        systems provide clean air, dilute
        and remove dust as well as natural
        and machine exhaust gases, and
        provide cooling for personnel and
        machinery. Ventilation systems need
        to run continuously 24 hours a day,
        throughout the year, which means
        uninterrupted power supply is a key
        requirement. The energy demand is
        significant and ventilation systems
        are currently the largest consumers
        of power in underground mines,
        accounting for as much as 50 percent
        of energy use.
           ABB’s protection and control
        solution offers the needed
        functionality and flexibility – with cost



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